Clutch-facing.



No Drawing.

.of unwoven felted short ii UNITED STATES PATENT OFFICE.

SUMNER SIMPSON, 0F BBIDGEPOBT, CONNECTICUT, ASSIGNOR TO THERAYBESTOB00., OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF CONNECTICUT.

CLUTCH-FACING:-

l atented June 25, 1918.

1,270,559. Specification of Letters Patent.

Application illed September 19, 1917. Serial 80.182332.

To all whom it may concern Be it known that I, SUMNER Smrson, a citizenof the United States, residing in the city" of Bridgeport, county ofFairfield, and

,State of Connecticut, have invented certain character referred to,which is uniform in character and uniform in density throughout itswearing surface and to a substantial depth of the latter; to provide aproduct, the essential body portion of which may be made of shortasbestos fiber united through the medium of a comminuted binder; toroduce a product of the above character vg 'ich can be formed tomicrometer measurements, bothas regards its width and thickness; toprovide a roduct havin the required co-efficient o friction, which has amaximum wearin resistance and is-capable of withstanding ightemperatures without physical or chemical change; toprovide a productwhich can be made of unspun short fiber, to. which may be added the dustor screenings of said fiber, united and held into i a compact andrelatively solid mass, substantially by the binding action of amaterial, eommlnuted or granular when dry; to

provide a preformed asbestos or'other suitable fibrous sheet which ma'beformed out r and out of which the facings' may be stamped or cuteither before or after saturation of the sheet with the binder; toprovide a process of makmg the above, product which eliminates theexpensive and numerous operations necessary in making a woven facing andwhich p rmits of the used the cheapest portion of the fiber, which formsa product havin a uniform character and density, not pose: 1e in thefibrous facings of the prior art to provide a process in which thematerial l ft after cutting or stamping out the facings can bere-treatcd to make a new sheet, thus reducing the waste material to aminimum; and indgeneral to rovide an improved product an process 0 thecharacter referred to.

In friction facin s, for motor vehicles and the like, the fol owin aredesirable, if not essential, characteristics which should be inherent ina good friction facing.

1. The co-eflicient of friction should be sufliciently high to meet allrequirements.

2. The facing should have a high wear resistin and heat resistingability.

3. he facing should be of uniform character and density so that even ifthe exposed surface wears away, there will be at'all times a uniformwearing surface.

4. The facing should be as free as possible from fibers which serve onlyas binders and are not themselves capable of standing abrasion or heatsuch as cotton, hemp or sisal fibers and paper.

5.' It is desirable to use as many short fibers as possible for thereason that the long fibers are relatively expensive.

6. The margin of profit makes it exceed ingly advantageous to have theprocess as economical and sim 1e as ossible.

7. The waste stoc shou d be reduced to a minimum.

8. The facing should be a tough, compact mass, free from any tendency tocause a siparation of its component parts and free 0 any tendency torevel. v

9. The facin should be capable of being punched or rilled andcountersunk for rivet holes without destroying its elliciency.

Asbestos from the mine run consists of relatively long fibers, known. inthe art as crude asbestos and relatively short fibers, known in the artas fiber asbestos. The

crude asbestos is the only portion that can be utilized for spinning andweaving; the fiber asbestos cannot be used for such purposeandaccordingly .low grade fiber asbestos has never been utilize in themanufacture of woven clutch facing. Heretofore no asbestos clutch facinghas been successfully made except from wovenfiber.

By means of the present invention, the low de asbestos fibers or shortfibers can be utilized to form the essential body portion of the clutchfacing. as heretofore stated. These fibers after being. felted areanently'united into a compact uniform mass 110.- A

by means of a comminuted binder carried 7 machine and formed intolaminated sheets this sheetof abnormal width, :1 large left from w ich'durin the process of manufacture in a suitable hquid vehicle.

One illustration of the manner in which the process ma be carried outis'as follows: The asbestos her or low grade short fiber as it comesfrom the mine 1s first ground in a suitable grinding machine or crusher.

This ground material is then put into a heater, mixed 'with water or oter liquid solution and beaten into a pulp. The wet pulp is thendelivered to a paper making of suitable width and thickness. From therethe sheet passes through suitable presses anddriers.

Preferably, this sheet is of suflicient width to permit of five or moreclutch facings to be stamped ,or cut out of its width, although thesheet may be made of any width ultable for meeting the particular reqirements. Either before or during the operation of cutting the sheet ispressed to proper sheets. Where clutch facmgs of the ring type is to bemade, they can be stamped or cut out of the body of the sheet form ng anendless annular or ring member. Bymaking these clutch facings in theform of an endless ring, the diflicul't-ies or objections incident toajointed woven ring are obviated. Clutch facings of the cone type canalso be formed from the sheet by cuttin out segments to-the radius ofthe cone an then forming them into proper shape. Where endless ringshaped faclngs are cut out of art of the sheet is necessaril no, furtherrings can be ormed. This otherwise waste material is saved by putting itback into the grinder and beate'rand runni it throughthe process as anew batch. e clutch facings are next impregnated or saturated insuitable dipping tanks with a binder. This binder may consist of eithera suitable vegetable oil or gum, or mineral oil and gum, or bitumens, ora combination of the same, the comminuted solid matter T e saturated orimpregnated material is then ut into a drying oven, which may be heate bclosed steam coils or otherwise preferab y to a temperature not inexcess 0 200 R, which drying step drives out-the solvent. .Aftertreating the'product is fit into a curing oven, where it is subjec ahigher heat, for example, from 250 to 500 'F., more or less. This stepgives the necessar hardness to the fabric or facing.

e invention is not limited to the details of product and process heredescribed, except as set forth in the appended claims.

I claim as my invention:

1. A clutch facing'having a wearing surface of uniform character anddensity throughout a substantial depth, the essential body portion ofsaid wearing surface being formed of unwoven felted short asbestosfiber, and a comminuted adhesive binder permanently uniting the fiberinto a solid compact mass.

2. A friction facing having a comsressed wearin surface,- of uniform'ensity throng out a substantial depth, the essential body. portion ofsaid wearin surface being formed of unwov'en felted ber havin a highabrasive resist character an a binder permanently'umting the fiber.

3. A clutch facin blank of abnormal width, the'essential ody portion ofwhich consists of a sheet of unwoven felted asbestOS fiber adapted to beformed into a plurality of :Eacmgs and capable of being per;-

-' manently united into a solid compact mass by intimately uniting thefiber'with a comminuted adhesive binder.

SUMNER smrson.

DISCLAIMER.

. 1,270,559.Sumner Simpson, 'Bridgeport, Coim. Curr-cu F AGING. Patentdated June 25, 1918. Disclaimer filed October 3, 1923, by the asignae,The Raybestoa Company. v v Hereby disclaim the article defined by saidclaim 2, exgept when such article is in the form of a relatively thindisk, or plpte, or strip, a side, or relatively wide fgoe, of whichreceives the wear, and wherein during its use no binding mediumaddilii'onal'to that used in its manufactur'e need be applied forpreventing material disintegmtion thereof.

[OM01 Gazette October 8:, 1983.]

